package com.atguigu.juc;

import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;

class MyCache {

    private volatile Map<String, Object> map = new HashMap<>();
    private ReadWriteLock readWriteLock = new ReentrantReadWriteLock();


    public void put(String key, Object value) {

        readWriteLock.writeLock().lock();
        try {
            System.out.println(Thread.currentThread().getName() + "\t ---开始写入" + key);
            try {
                TimeUnit.MICROSECONDS.sleep(300);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            map.put(key, value);
            System.out.println(Thread.currentThread().getName() + "\t--- 写入完成");
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            readWriteLock.writeLock().unlock();
        }

    }

    public void get(String key) {

        readWriteLock.readLock().lock();
        try {
            System.out.println(Thread.currentThread().getName() + "\t ---开始读取" + key);
            Object result = map.get(key);
            System.out.println(Thread.currentThread().getName() + "\t ---读取完成" + result);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            readWriteLock.readLock().unlock();
        }

    }
}


public class ReadWriteLockDemo {

    public static void main(String[] args) {

        MyCache myCache = new MyCache();

        for (int i = 0; i < 5; i++) {
            final int tmepInt = i;
            new Thread(() -> {
                myCache.put("k" + tmepInt, "v" + tmepInt);
            }, String.valueOf(i)).start();
        }

        for (int i = 0; i < 5; i++) {
            final int tmepInt = i;
            new Thread(() -> {
                myCache.get("k" + tmepInt);
            }, String.valueOf(i)).start();
        }

    }

}
